“Focus” is about con artists, and the title refers to the fact that humans are easily distracted and thus subject to being conned. Some of us are easier marks than others, of course. I, for one, am almost always fooled by the tricks in con-artist movies. Even when I should know better, I think, “Uh-oh! They blew it! Their caper’s not going to work! How will they get out of this?” And then it turns out they knew what they were doing all along, the setbacks were part of the plan, and I am delighted. Every time.

Co-written and directed by the duo of Glenn Ficarra and John Requa (“I Love You Philip Morris,” “Crazy Stupid Love”), “Focus” is a crime caper with a romantic angle, aimed at adults, and reminiscent of “Out of Sight” or “Duplicity.” It doesn’t have any great elements, but it does have several good ones, including its stars, Will Smith and Margot Robbie. Smith plays Nicky, an experienced, unflappable conman who’s particularly gifted in the art of pickpocketing. He meets Jess (Robbie), an up-and-coming thief — and, not incidentally, a smokin’ hot babe — who wants to join Nicky’s team and learn the tricks of the trade. They collaborate on some thievery and some sex, each finding the other’s skills in both fields to be more than adequate.

Nicky’s team of light-fingered felons, most of them nameless and inessential to the story, are a wonder to behold. In a sequence set in New Orleans the week of a major tourist-drawing sporting event (prime time for pickpockets), we see them in action, their smooth choreography of distractions and handoffs as flawless as a ballet. Nicky says it’s best to stick to small stuff and get rich by volume, urging Jess to stay away from big scores, though he doesn’t always follow his own advice. A few allusions to Nicky’s personal gambling habits and an interlude with an avid high-stakes bettor (played by BD Wong) suggest a variety of ways this story could go.

It’s ultimately no more creative or genre-defying than the typical movie about con artists, and it has the same limitation as most of them — namely, when the main characters are inveterate liars, it’s hard to know when their emotions are sincere. We can be entertained, thrilled, and amused by their escapades, but we don’t really CONNECT with them, you know? That’s a problem when, as in this instance, the con artists are romantically involved. We’re not going to let ourselves be caught up in the romance when we’re always on guard, suspecting one or both of them is playing the other one.

Nonetheless, “Focus” keeps us guessing by jumping ahead a few years and moving to a new location for its second half, and by introducing a romantic rival, wealthy auto-racing maven Garriga (Rodrigo Santoro), and his gruff, fearless bodyguard (Gerald McRaney, gloriously cranky). These two, along with Nicky’s corpulent co-conspirator Farhad (Adrian Martinez), are wild cards in a story that’s really about Nicky and Jess, whom we like despite being unsure of their motives. Smith’s star power remains bright after all these years (a marvel in itself, given how few B-or-better movies he’s actually made), and Robbie, a charismatic new talent, holds her own with him. And yes, I was fooled, and subsequently delighted.